The present invention relates generally to ring binders and more particularly to a novel ring binder.
Referring to FIG. 1, a side view, broken away in part, of one type of prior art ring binder 11 is illustrated. Binder 11 comprises a pair of superimposed sheets 13-1 and 13-2 of thermoplastic material, preferably vinyl, and three rigid, spaced-apart, stiffener panels 15-1, 15-2 and 15-3, respectively. Stiffener panels 15-1 through 15-3, which are appropriately sized to provide support to the rear cover, spine and front cover, respectively, of binder 11, are sandwiched between sheets 13-1 and 13-2. Sheets 13-1 and 13-2 are heat-sealed to one another around their respective peripheries and on either side of panel 15-2 to define the rear cover 17-1, spine 17-2, and front cover 17-3, respectively, of binder 11, spine 17-2 being joined to rear cover 17-1 and to front cover 17-3 by hinge lines 19-1 and 19-2, respectively. A snap-ring assembly 21 is riveted or otherwise fastened directly to rear cover 17-1. Spine 17-2 is free to pivot away from ring assembly 21 in the direction indicated by arrow 22 to provide convenient access to assembly 21. As can be seen, the width of spine 17-2 is great enough to enable covers 17-1 and 17-3 to clear the snap rings of assembly 21. This type of binder is particularly well-suited to uses requiring oversized snap rings for maintaining a great number of loose-leaf sheets. Such a binder, however, requires excessive shelf space, and it is difficult to grasp at the wide, flat and pivotable spine 17-2.
In U.S. Pat. No. 5,222,825, inventor Wyant, which issued Jun. 29, 1993 and which is incorporated herein by reference, there is disclosed a round back binder which is directed to overcoming some of the problems mentioned above. More specifically, the binder disclosed therein comprises a rectangular stiffener board and a sheet retaining assembly. The stiffener board is provided in its first surface with at least three spaced parallel partially-penetrating channels medially located between the side edges of the board. Each channel defines a hinge line extending along the height of the stiffener board. The sheet retaining assembly is mounted on the first surface of the board adjacent to the channels but outside the medial section of the board where the channels are located. The binder, thus structured, allows the stiffener board to define front and rear covers of the binder interconnected by the medial section which is foldable conformingly about the retaining assembly. The stiffener board may be covered by a pair of surface sheets, preferably fabricated from canvas material. One of the surface sheets, the interior surface sheet, is secured to the channeled surface of the stiffener board by adhesive material. The adhesive may be distributed so as to cause the interior surface sheet to extend conformingly into the channels. This interior surface sheet faces inwardly in the assembled binder. A second sheet, the exterior surface sheet, preferably also canvas, covers the opposite surface of the stiffener, extends around the edges thereof and is bonded against the interior surface of the interior surface sheet.
In PCT application No. PCT/US93/03786, which was filed Apr. 21, 1993 and which is incorporated herein by reference, there is disclosed another example of a ring binder having a curvable spine. More specifically, the ring binder disclosed therein includes two rectangular polymeric sheets of sufficient size to form the entire inner and outer covering of the binder. Disposed between the sheets is a semi-rigid rectangular insert. The insert is formed or machined with two parallel partially-penetrating hinge grooves which divide the insert into three zones. The front zone and back zone are dimensioned to be approximately the same length and width as the cover panels of the binder. The spine zone is dimensioned to be approximately the same length and width as the spine. A plurality of parallel partially-penetrating spine grooves are provided between the hinge grooves on the insert. The spine grooves act like the hinge grooves and allow the spine to transform from a flat configuration to a curved configuration in which the inner surface of the spine is concave about the longitudinal axis of the spine. The spacing and number of spine grooves is selected to result in a smooth curve on the outside surface of the spine when the binder is closed. The ring hardware is preferably mounted, by conventional rivets and holes, to one or the other of the covers, rather than to the spine.
In U.S. Pat. No. 4,856,817, inventor Moor, which issued Aug. 15, 1989 and which is incorporated herein by reference, there is disclosed an easy-grip binder having opposed spine recesses for ease of grasping. More specifically, the binder disclosed therein comprises a front cover board, a rear cover board and a spine board positioned between the front cover board and the rear cover board so as to define front and rear hinge lines therebetween. Inside and outside cover sheets are laminated to the spine board and cover boards on opposite sides in the customary manner. The spine recesses are defined by cutouts on opposite sides of the spine board and matching cutouts on the cover boards. The outside cover sheet is depressed conformingly into the cutouts. A hand-hold recess is provided opposite the spine recesses. This latter recess is defined by providing hand-hold cutouts along the edges of the cover boards which are remote from the spine. The inside and outside covers are conformingly fitted into these cutouts. Preferably, the outside cover sheet has a ribbed contour in the region of the spine recesses to facilitate finger gripping.
In U.S. Pat. No. 5,219,437, inventors Moor et al., which issued Jun. 15, 1993 and which is incorporated herein by reference, there is disclosed a fabric covered book cover. More specifically, the book cover disclosed therein comprises an inside fabric surface adjacent the contents of the book cover and an outside fabric surface opposite the inside surface which comes into contact with the hand when the book cover is carried. In a more preferred embodiment, the fabric material is woven nylon or another synthetic material. The book cover includes two leafboards which are rectangular and formed by first and second stiffening members, each stiffening member when incorporated into the book cover has three outside edges which form the periphery of the cover and one internal edge. The fabric encases the stiffening members which are spaced apart on the fabric. A peripheral seam is located along and immediately outside the outside edges of the stiffening members. A pair of parallel and spaced seams running along and immediately adjacent the internal edges of the stiffening members maintain the position of both stiffening members within the fabric. In a more preferred embodiment, the stiffening member is cardboard, pressed paper or the like. In a more preferred embodiment, a padding member can be positioned between the stiffening member and the fabric in each of the front and back leafboards. The spine is formed by a portion of fabric which connects the front and back leafboards. The spine includes a plurality of parallel longitudinal seams which enable the spine to curl flexibly such that it is easily cupped in the palm of the hand. In a more preferred embodiment, the spine has a padding member encased therein and the plurality of seams maintain a constant amount of the padding material between each parallel stitched seam and thus prevent the padding member from accumulating unevenly in the spine.
In U.S. Pat. No. 3,572,957, inventor Strassberg, which issued Mar. 30, 1971 and which is incorporated herein by reference, there is disclosed a ribbed-backbone binder construction for use in a looseleaf binder. More specifically, the binder construction disclosed therein comprises a single unit board stiffener which includes front and rear cover sections and a backbone section having elongated openings, running almost the entire width of the stiffener and positioned on both sides of a center strip, forming an element of the support strip for the ring mechanism. The stiffener is completely covered by sheets of thermoplastic material which are welded around the edges and through the elongated openings of the stiffener. A typical snap ring mechanism may then be riveted into position against the support strip formed by the cover sheets and the stiffener, and the elongated openings and the material therebetween form a plurality of ribs and hinges which may be folded around the ring mechanism. The ribs and hinges may then be expanded beyond the widths of the support strip as there is increased capacity within the binder. The ribbed and hinged portion may also be gripped by the hand, the hinges allowing the covers to lie completely flat.